In an effort to extend the lifespan of its pipelines and protect the environment from harmful spills, Barwon Water is investing $50 million over the next five years on upgrades and repairs to its sewer system, spanning Geelong, the Colac Otway Shire, Surf Coast, and the Bellarine.
Barwon Water Managing Director, Shaun Cumming, said the significant program was part of Barwon Water’s commitment to its customers, as outlined in the 2023 Price Submission. “Works in the program will renew hundreds of pipes, extending their lifespan and minimising the risk of blockages and sewer spills.” Mr Cumming highlighted the advanced techniques employed in the initiative.
“Our contractors utilise CCTV to monitor the condition of ageing sewer pipes. “After high-pressure water cleaning, structural liners, often polyester coated felt tube liners, are inserted or pulled into the existing pipeline via maintenance holes, essentially creating a pipe-within-a pipe. “This innovative approach reinforces and extends the life of the pipes, while reducing disruption on customers.”
Sensing a spill-free future
The sewer upgrade investment program of works is only part of the picture, with Barwon Water conducting research with partners on a number of different technologies to help it move towards zero spills in the future. One of these initiatives was a sensor trial in the Lorne sewer network, with technology that in the future may be able to be used to preemptively address sewer overflows.
The Lorne sewer network was chosen due to its smaller size and self-contained nature of the system, which made it suitable for a trial of this technology. The network, like all sewer networks, suffered from occasional overflows due to various factors, including tree roots and improper disposals. Mr Cumming said the trial aligned with Barwon Water’s aim to provide innovative and reliable services to its customers.
“The sensors track the depth and flow of sewerage at various points in the system, transmitting valuable data to Barwon Water staff. “Our goal is to use this data to swiftly identify partial blockages and take pre-emptive action to remove them before overflows occur.” The trial involved installing sensors at 15 locations along the Lorne foreshore, and as part of a strategic partnership with Deakin University scholars developing an algorithm to analyse the gathered sensor data.
During the trial, a few blockages were detected at their early stages, and no significant sewer spill events occurred. The potential success of the trial could lead to a broader rollout of these sensors across the region’s sewer network. This initiative showcases Barwon Water’s commitment to leveraging technology, partnerships and innovation to enhance the reliability of the sewer network, protect the environment, and ensure sustainable wastewater management.
Sewer simulator
Coupled with this research was another project with Deakin University that offered another way to revolutionise urban wastewater management. The initiative, funded by Barwon Water and Victoria’s Intelligent Water Networks, presents experimental results shedding light on how extended bottom blockages and discrete top blockages impact flow conditions in gravity sewer systems.
A transparent circular open channel experimental system, constructed at Deakin University, simulated a gravity sewer pipe. Extended bottom and discrete top blockages, simulating foreign objects, wipes, sediment deposits, tree roots and fatbergs, were inserted into the system and tested with varying flow rates.
The impact of these blockages was assessed by measuring the flow depth just upstream of the blockage. The results offer fundamental knowledge essential for cost-effective sewer blockage detection through distributed sewer depth monitoring. “Understanding how different types of blockages affect flow conditions is crucial for developing effective and targeted solutions,” Mr Cumming said.
“Our research provides insights into the dynamics of sewer systems, enabling us to advance the field of sewer blockage prevention.”
Key findings
Blockages in sewer pipe networks can lead to various issues, including spills and service interruptions. While “smart sewer” monitoring systems similar to that trialled in Lorne exist, their data analytics often rely on simple threshold alarms, resulting in false positives and negatives.
This knowledge gap is being addressed by the research project, which aims to enhance understanding through comprehensive experimental results. Key highlights of the research:
- Both types of blockages (extended bottom blockages and discrete top blockages) were found to significantly increase the upstream flow depth under certain conditions
- The impact of extended bottom blockages is proportional to the height of blockage and the flow rate and the change in upstream flow depth is gradual, presenting opportunities for early detection
- Discrete top blockages are typically disguised and unnoticeable under low flow rates, but can suddenly induce choking when the flow depth reaches the blockage under high flow rates
The outcomes of this research have far-reaching implications for sewer management, providing valuable data for the development of advanced sewer monitoring systems.
The power of knowledge sharing
Barwon Water is committed to collaborating with stakeholders and communities to implement sustainable solutions that protect our environment. Public education is also a key aspect of Barwon Water’s approach to managing the sewerage system. “We have a campaign called Don’t flush it!, which urges customers to not treat their toilet like a rubbish bin and to only flush the ‘three Ps’ (pee, poo and toilet paper).”
The campaign targets people who often dispose of things like flushable wet wipes, cotton buds, sanitary items, food scraps and cooking fats and oils in their toilets and drains, leading to blockages. “This is a serious issue as these blockages can lead to raw sewage spilling out into streets or creeks, or even people’s properties.”
Not only do blockages wreak havoc with Barwon Water’s sewerage systems, residents and businesses are often left with expensive plumbing and repair bills.
